The Naked Scientists
  • Login
  • Register
  • Podcasts
      • The Naked Scientists
      • eLife
      • Naked Genetics
      • Naked Astronomy
      • In short
      • Naked Neuroscience
      • Ask! The Naked Scientists
      • Question of the Week
      • Archive
      • Video
      • SUBSCRIBE to our Podcasts
  • Articles
      • Science News
      • Features
      • Interviews
      • Answers to Science Questions
  • Get Naked
      • Donate
      • Do an Experiment
      • Science Forum
      • Ask a Question
  • About
      • Meet the team
      • Our Sponsors
      • Site Map
      • Contact us

User menu

  • Login
  • Register
  • Home
  • Help
  • Search
  • Tags
  • Recent Topics
  • Login
  • Register
  1. Naked Science Forum
  2. Non Life Sciences
  3. Physics, Astronomy & Cosmology
  4. How does this experiment work?
« previous next »
  • Print
Pages: [1]   Go Down

How does this experiment work?

  • 4 Replies
  • 5427 Views
  • 0 Tags

0 Members and 1 Guest are viewing this topic.

Offline thebrain13 (OP)

  • Hero Member
  • *****
  • 517
  • Activity:
    0%
How does this experiment work?
« on: 29/04/2010 04:49:16 »
I was doing a couple experiments using the magnets around my house, and there was one experiment I did not get. This is how it works. I had a permanent magnet on a smooth table. I also had some paperclips, and a piece of ferromagnetic material (the metal on a pair of scissors). What I did is I put the scissors next to the magnet and saw how the scissors would affect the strength of the magnetism. I could see how the strength of the force would change by moving the magnet slowly towards the paperclip to see how close I could get before the paperclip flew over to the magnet.

What I found was that, if you put the metal "behind" the magnet, meaning the metal was on the opposite side of the magnet in relation to the paperclip. So oriented in this way paperclip(left) magnet(middle) metal(right). When I did this I got the result I was expecting, this increases the strength of magnetic force, the magnet could pull the paperclip a further distance, than if there was no metal behind it.

However when you do the inverse of this experiment, when you put the metal in between the magnet and the paperclip. It doesn't increase the strength of magnetism, it reduces it. The magnet can get even closer to the paperclip than if the metal wasn't there at all. Why does this happen?
Logged
 



Offline Soul Surfer

  • Naked Science Forum King!
  • ******
  • 3389
  • Activity:
    0%
  • Thanked: 8 times
  • keep banging the rocks together
    • ian kimber's web workspace
How does this experiment work?
« Reply #1 on: 29/04/2010 08:54:57 »
The presence of ferromagnetic material between a magnet and an object can act as a magnetic screen if it is a thin layer placed across the path of the field  however if it is placed along the direction of the field the induced poles in the material can effectively increase the field at a distance from the magnet
Logged
Learn, create, test and tell
evolution rules in all things
God says so!
 

Offline thebrain13 (OP)

  • Hero Member
  • *****
  • 517
  • Activity:
    0%
How does this experiment work?
« Reply #2 on: 29/04/2010 16:25:55 »
Quote from: Soul Surfer on 29/04/2010 08:54:57
The presence of ferromagnetic material between a magnet and an object can act as a magnetic screen if it is a thin layer placed across the path of the field  however if it is placed along the direction of the field the induced poles in the material can effectively increase the field at a distance from the magnet

I always thought that the magnetic field strength was just the composite of all the individual magnetic fields. I thought the "magnetic screen" was just an illusion. Do you know what the effect is called?

Another note about the experiment is that the magnetic field lines point in the direction of the paperclip. That is, the north and the south side of the magnet is aligned from left to right. So to be more specific.

the lineup is this.  (paperclip) (ferromagnetic material) (north end of magnet) (south end of magnet)
Logged
 

Offline Geezer

  • Naked Science Forum King!
  • ******
  • 8314
  • Activity:
    0%
  • Thanked: 8 times
  • "Vive la résistance!"
How does this experiment work?
« Reply #3 on: 29/04/2010 18:15:07 »
You are altering the magnetic circuit in your experiments. By introducing pieces of steel, you are altering the path of least resistance to the magnetic flux.
Logged
There ain'ta no sanity clause, and there ain'ta no centrifugal force æther.
 

Offline tommya300

  • Hero Member
  • *****
  • 654
  • Activity:
    0%
  • Thanked: 4 times
How does this experiment work?
« Reply #4 on: 20/05/2010 07:15:00 »
Quote from: thebrain13 on 29/04/2010 04:49:16
I was doing a couple experiments using the magnets around my house, and there was one experiment I did not get. This is how it works. I had a permanent magnet on a smooth table. I also had some paperclips, and a piece of ferromagnetic material (the metal on a pair of scissors). What I did is I put the scissors next to the magnet and saw how the scissors would affect the strength of the magnetism. I could see how the strength of the force would change by moving the magnet slowly towards the paperclip to see how close I could get before the paperclip flew over to the magnet.

What I found was that, if you put the metal "behind" the magnet, meaning the metal was on the opposite side of the magnet in relation to the paperclip. So oriented in this way paperclip(left) magnet(middle) metal(right). When I did this I got the result I was expecting, this increases the strength of magnetic force, the magnet could pull the paperclip a further distance, than if there was no metal behind it.

However when you do the inverse of this experiment, when you put the metal in between the magnet and the paperclip. It doesn't increase the strength of magnetism, it reduces it. The magnet can get even closer to the paperclip than if the metal wasn't there at all. Why does this happen?

Johann Carl Friedrich Gauss I presume.

An easy way to visualize the magnetic field is to use an old plastic tray tape the magnet to the center outside bottom of it. Turn it back over and block up each end just enough of clearance. Sprinkle iron filings in the top where the magnet would be underneath it. Watch and see the mag field. Now outside this tray underside place the steel sizzers orientating them as you did the way you explained before. Watch the filings change position.  This help?
« Last Edit: 20/05/2010 07:25:33 by tommya300 »
Logged
 



  • Print
Pages: [1]   Go Up
« previous next »
Tags:
 
There was an error while thanking
Thanking...
  • SMF 2.0.15 | SMF © 2017, Simple Machines
    Privacy Policy
    SMFAds for Free Forums
  • Naked Science Forum ©

Page created in 0.362 seconds with 38 queries.

  • Podcasts
  • Articles
  • Get Naked
  • About
  • Contact us
  • Advertise
  • Privacy Policy
  • Subscribe to newsletter
  • We love feedback

Follow us

cambridge_logo_footer.png

©The Naked Scientists® 2000–2017 | The Naked Scientists® and Naked Science® are registered trademarks created by Dr Chris Smith. Information presented on this website is the opinion of the individual contributors and does not reflect the general views of the administrators, editors, moderators, sponsors, Cambridge University or the public at large.